I am working on using snappy api to develop some algorithms. But I have not found many document of it. Does any one have any clues of how to use a model with python script, which can be found in SNAP-desktop? This is a general question.
To tell more about this. To use the model in SNAP-desktop Radar-Radiometric-Calibrate, we can write the script like the following. It is easy to find the relevant parameters in the script and SNAP-desktop UIs.
However, if I am trying to use another model, i.e. “SNAP-desktop-Radar-Apply Orbit File”, how do I know the parameter names and the model names? Like what can I replace the “Calibration” for the above codes? And how to find them?
Usually when you try to use a model like SNAP-desktop with snappy, you can refer to this:
The list of the operators (models) can be found typing “gpt” in command line.
Here are all of them supported in 6.0:
- Aatsr.SST Computes sea surface temperature (SST) from (A)ATSR products.
- AATSR.Ungrid Ungrids (A)ATSR L1B products and extracts geolocation and pixel field of view data.
- AdaptiveThresholding Detect ships using Constant False Alarm Rate detector.
- AddElevation Creates a DEM band
- AddLandCover Creates a land cover band
- AerosolRetrieval.S2.Master Aerosol retrieval from S2 MSI following USwansea algorithm as used in GlobAlbedo project.
- ALOS-Deskewing Deskewing ALOS product
- Apply-Orbit-File Apply orbit file
- Arc.SST Computes sea surface temperature (SST) from (A)ATSR products.
- ArviOp Atmospherically Resistant Vegetation Index belongs to a family of indices with built-in atmospheric corrections.
- AzimuthFilter Azimuth Filter
- Back-Geocoding Bursts co-registration using orbit and DEM
- BandMaths Create a product with one or more bands using mathematical expressions.
- BandMerge Allows copying raster data from any number of source products to a specified 'master' product.
- BandSelect Creates a new product with only selected bands
- Bi2Op The Brightness index represents the average of the brightness of a satellite image.
This index is sensitive to the brightness of soils which is highly correlated with the humidity and the presence of salts in surface
- Binning Performs spatial and temporal aggregation of pixel values into cells ('bins') of a planetary grid
- BiOp The Brightness index represents the average of the brightness of a satellite image.
- BiophysicalOp The 'Biophysical Processor' operator retrieves LAI from atmospherically corrected Sentinel-2 products
- c2rcc.landsat8 Performs atmospheric correction and IOP retrieval with uncertainties on Landsat-8 L1 data products.
- c2rcc.meris Performs atmospheric correction and IOP retrieval with uncertainties on MERIS L1b data products.
- c2rcc.meris4 Performs atmospheric correction and IOP retrieval with uncertainties on MERIS L1b data products from the 4th reprocessing.
- c2rcc.modis Performs atmospheric correction and IOP retrieval on MODIS L1C_LAC data products.
- c2rcc.msi Performs atmospheric correction and IOP retrieval with uncertainties on Sentinel-2 MSI L1C data products.
- c2rcc.olci Performs atmospheric correction and IOP retrieval with uncertainties on SENTINEL-3 OLCI L1B data products.
- c2rcc.seawifs Performs atmospheric correction and IOP retrieval on SeaWifs L1C data products.
- c2rcc.viirs Performs atmospheric correction and IOP retrieval on Viirs L1C data products.
- Calibration Calibration of products
- CCICloudShadow Algorithm detecting cloud shadow...
- Change-Detection Change Detection.
- CiOp Colour Index was developed to differentiate soils in the field.
In most cases the CI gives complementary information with the BI and the NDVI.
Used for diachronic analyses, they help for a better understanding of the evolution of soil surfaces.
- CloudProb Applies a clear sky conservative cloud detection algorithm.
- Coherence Estimate coherence from stack of coregistered images
- Collocate Collocates two products based on their geo-codings.
- Convert-Datatype Convert product data type
- CreateStack Collocates two or more products based on their geo-codings.
- Cross-Channel-SNR-Correction Compute general polarimetric parameters
- Cross-Correlation Automatic Selection of Ground Control Points
- CrossResampling Estimate Resampling Polynomial using SAR Image Geometry, and Resample Input Images
- DeburstWSS Debursts an ASAR WSS product
- DEM-Assisted-Coregistration Orbit and DEM based co-registration
- Double-Difference-Interferogram Compute double difference interferogram
- DviOp Difference Vegetation Index retrieves the Isovegetation lines parallel to soil line
- EAP-Phase-Correction EAP Phase Correction
- Ellipsoid-Correction-GG GG method for orthorectification
- Ellipsoid-Correction-RD Ellipsoid correction with RD method and average scene height
- EMClusterAnalysis Performs an expectation-maximization (EM) cluster analysis.
- Enhanced-Spectral-Diversity Estimate constant range and azimuth offsets for the whole image
- Fill-DEM-Hole Fill holes in given DEM product file.
- Find-Image-Pair DB query to find matching image pair
- FlhMci Computes fluorescence line height (FLH) or maximum chlorophyll index (MCI).
- Flip flips a product horizontal/vertical
- FUB.Water FUB/WeW WATER Processor to retrieve case II water properties and atmospheric properties
- FuClassification Colour classification based on the discrete Forel-Ule scale.
- GemiOp This retrieves the Global Environmental Monitoring Index (GEMI).
- GenericRegionMergingOp The 'Generic Region Merging' operator computes the distinct regions from a product
- GLCM Extract Texture Features
- GndviOp Green Normalized Difference Vegetation Index
- GoldsteinPhaseFiltering Phase Filtering
- GRD-Post Applies GRD post-processing
- Idepix.Envisat.Meris Pixel identification and classification for MERIS.
- Idepix.Landsat8.OLI Pixel identification and classification for Landsat-8 OLI instrument.
- Idepix.OrbView2.Seawifs Pixel identification and classification for SeaWiFS.
- Idepix.Probav.Vegetation Pixel identification and classification for PROBA-V.
- Idepix.Sentinel2 Pixel identification and classification for Sentinel-2.
- Idepix.Sentinel3.Olci Pixel identification and classification for OLCI.
- Idepix.SuomiNpp.Viirs Pixel identification and classification for VIIRS.
- Idepix.TerraAqua.Modis Pixel identification and classification for MODIS.
- Image-Filter Common Image Processing Filters
- Import-Vector Imports a shape file into a product
- IntegerInterferogram Create integer interferogram
- Interferogram Compute interferograms from stack of coregistered S-1 images
- IpviOp Infrared Percentage Vegetation Index retrieves the Isovegetation lines converge at origin
- IreciOp Inverted red-edge chlorophyll index
- KDTree-KNN-Classifier KDTree KNN classifier
- KMeansClusterAnalysis Performs a K-Means cluster analysis.
- KNN-Classifier K-Nearest Neighbour classifier
- Land-Cover-Mask Perform decision tree classification
- Land-Sea-Mask Creates a bitmask defining land vs ocean.
- LandWaterMask Operator creating a target product with a single band containing a land/water-mask.
- LinearToFromdB Converts bands to/from dB
- Maximum-Likelihood-Classifier Maximum Likelihood classifier
- McariOp Modified Chlorophyll Absorption Ratio Index, developed to be responsive to chlorophyll variation
- Mci.s2 Computes maximum chlorophyll index (MCI) for Sentinel-2 MSI.
- Merge Allows merging of several source products by using specified 'master' as reference product.
- Meris.CorrectRadiometry Performs radiometric corrections on MERIS L1b data products.
- Meris.N1Patcher Copies an existing N1 file and replaces the data for the radiance bands
- Minimum-Distance-Classifier Minimum Distance classifier
- MndwiOp Modified Normalized Difference Water Index, allowing for the measurement of surface water extent
- Mosaic Creates a mosaic out of a set of source products.
- MphChl This operator computes maximum peak height of chlorophyll (MPH/CHL).
- Msavi2Op This retrieves the second Modified Soil Adjusted Vegetation Index (MSAVI2).
- MsaviOp This retrieves the Modified Soil Adjusted Vegetation Index (MSAVI).
- MtciOp The Meris Terrestrial Chlorophyll Index, aims at estimating the Red Edge Position (REP).
This is the maximum slant point in the red and near-infrared region of the vegetal spectral reflectance.
It is useful for observing the chlorophyll contents, vegetation senescence, and stress for water and nutritional deficiencies, but it is less suitable for land classification
- Multi-size Mosaic Creates a multi-size mosaic out of a set of source products.
- Multi-Temporal-Speckle-Filter Speckle Reduction using Multitemporal Filtering
- Multilook Averages the power across a number of lines in both the azimuth and range directions
- Ndi45Op Normalized Difference Index using bands 4 and 5
- NdpiOp The normalized differential pond index, combines the short-wave infrared band-I and the green band
- NdtiOp Normalized difference turbidity index, allowing for the measurement of water turbidity
- NdviOp The retrieves the Normalized Difference Vegetation Index (NDVI).
- Ndwi2Op The Normalized Difference Water Index, allowing for the measurement of surface water extent
- NdwiOp The Normalized Difference Water Index was developed for the extraction of water features
- Object-Discrimination Remove false alarms from the detected objects.
- Offset-Tracking Create velocity vectors from offset tracking
- Oil-Spill-Clustering Remove small clusters from detected area.
- Oil-Spill-Detection Detect oil spill.
- Orientation-Angle-Correction Perform polarization orientation angle correction for given coherency matrix
- Oversample Oversample the datset
- OWTClassification Performs an optical water type classification based on atmospherically corrected reflectances.
- PCA Performs a Principal Component Analysis.
- PduStitching Stitches multiple SLSTR L1B product dissemination units (PDUs) of the same orbit to a single product.
- PhaseFilter Interferometric phase filtering
- PhaseToDisplacement Phase To Displacement Conversion along LOS
- PhaseToElevation DEM Generation
- PhaseToHeight Phase to Height conversion
- PixEx Extracts pixels from given locations and source products.
- Polarimetric-Classification Perform Polarimetric classification of a given product
- Polarimetric-Decomposition Perform Polarimetric decomposition of a given product
- Polarimetric-Matrices Generates covariance or coherency matrix for given product
- Polarimetric-Parameters Compute general polarimetric parameters
- Polarimetric-Speckle-Filter Polarimetric Speckle Reduction
- Principle-Components Principle Component Analysis
- ProductSet-Reader Adds a list of sources
- PssraOp Pigment Specific Simple Ratio, chlorophyll index
- PviOp Perpendicular Vegetation Index retrieves the Isovegetation lines parallel to soil line. Soil line has an arbitrary slope and passes through origin
- Rad2Refl Provides conversion from radiances to reflectances or backwards.
- Random-Forest-Classifier Random Forest based classifier
- RangeFilter Range Filter
- RayleighCorrection Performs radiometric corrections on OLCI, MERIS L1b and S2 MSI data products.
- Read Reads a data product from a given file location.
- ReflectanceToRadianceOp The 'Reflectance To Radiance Processor' operator retrieves the radiance from reflectance using Sentinel-2 products
- ReipOp The red edge inflection point index
- Remove-GRD-Border-Noise Mask no-value pixels for GRD product
- RemoveAntennaPattern Remove Antenna Pattern
- ReplaceMetadata Replace the metadata of the first product with that of the second
- Reproject Reprojection of a source product to a target Coordinate Reference System.
- Resample Resampling of a multi-size source product to a single-size target product.
- RiOp The Redness Index was developed to identify soil colour variations.
- RviOp Ratio Vegetation Index retrieves the Isovegetation lines converge at origin
- S2.WaterVapour Water Vapour retrieval from S2 MSI
- S2repOp Sentinel-2 red-edge position index
- S2tbx-Reproject Reprojection of a source product to a target Coordinate Reference System.
- SAR-Mosaic Mosaics two or more products based on their geo-codings.
- SAR-Simulation Rigorous SAR Simulation
- SARSim-Terrain-Correction Orthorectification with SAR simulation
- SaviOp This retrieves the Soil-Adjusted Vegetation Index (SAVI).
- SetNoDataValue Set NoDataValueUsed flag and NoDataValue for all bands
- SliceAssembly Merges Sentinel-1 slice products
- SmacOp Applies the Simplified Method for Atmospheric Corrections of Envisat MERIS/(A)ATSR measurements.
- SmosNetcdfExport Exports SMOS Earth Explorer products to NetCDF format.
- SnaphuExport Export data and prepare conf file for SNAPHU processing
- SnaphuImport Ingest SNAPHU results into InSAR product.
- Speckle-Divergence Detect urban area.
- Speckle-Filter Speckle Reduction
- SRGR Converts Slant Range to Ground Range
- Stack-Averaging Averaging multi-temporal images
- Stack-Split Writes all bands to files.
- StampsExport Export data for StaMPS processing
- StatisticsOp Computes statistics for an arbitrary number of source products.
- SubGraph Encapsulates a graph within a graph.
- Subset Create a spatial and/or spectral subset of a data product.
- Supervised-Wishart-Classification Perform supervised Wishart classification
- TemporalPercentile Computes percentiles over a given time period.
- Terrain-Correction RD method for orthorectification
- Terrain-Flattening Terrain Flattening
- Terrain-Mask Terrain Mask Generation
- ThermalNoiseRemoval Removes thermal noise from products
- Three-passDInSAR Differential Interferometry
- TileWriter Writes a data product to a tiles.
- TndviOp Transformed Normalized Difference Vegetation Index retrieves the Isovegetation lines parallel to soil line
- ToolAdapterOp Tool Adapter Operator
- TopoPhaseRemoval Compute and subtract TOPO phase
- TOPSAR-Deburst Debursts a Sentinel-1 TOPSAR product
- TOPSAR-Merge Merge subswaths of a Sentinel-1 TOPSAR product
- TOPSAR-Split Creates a new product with only the selected subswath
- TsaviOp This retrieves the Transformed Soil Adjusted Vegetation Index (TSAVI).
- Undersample Undersample the datset
- Unmix Performs a linear spectral unmixing.
- Update-Geo-Reference Update Geo Reference
- Warp Create Warp Function And Get Co-registrated Images
- WdviOp Weighted Difference Vegetation Index retrieves the Isovegetation lines parallel to soil line. Soil line has an arbitrary slope and passes through origin
- Wind-Field-Estimation Estimate wind speed and direction
- Write Writes a data product to a file.
When you try to figure out which parameters need to be specified. Use the following code below:
from snappy import GPF
GPF.getDefaultInstance().getOperatorSpiRegistry().loadOperatorSpis()
op_spi = GPF.getDefaultInstance().getOperatorSpiRegistry().getOperatorSpi('OperatorName')
print('Op name:', op_spi.getOperatorDescriptor().getName())
print('Op alias:', op_spi.getOperatorDescriptor().getAlias())
param_Desc = op_spi.getOperatorDescriptor().getParameterDescriptors()
for param in param_Desc:
print(param.getName(), "or", param.getAlias())